Why Haiti is susceptible to catastrophic earthquakes

The 21st century has not been any less kind. Saturday's strong earthquake left many dead and thousands injured. Eleven years ago, a temblor had killed thousands, if not hundreds of thousand.

Haiti is located near the intersection of the two tectonic plates which make up the Earth’s crust. When these plates are in contact with each other, friction can cause earthquakes. Haiti is also very densely populated. Many of Haiti's buildings can withstand hurricanes, not earthquakes. These buildings are strong enough to withstand strong winds, but they can be smashed if the ground shakes.

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WHAT MAKES HAITI PRONE to EARTHQUAKES

The Earth's crust is composed of tectonic plates, which move. Haiti is located at the intersection of two plates -- the North American and Caribbean plates.

Multiple fault lines run between the plates and cut through the island of Hispaniola. Haiti shares this island with the Dominican Republic. Worse, not all fault lines behave in the same way.

Rich Briggs, a geologist at U.S. Geological Survey’s Geologic Hazards Sciences Center, stated that "Hispaniola is in a spot where plates transition between smashing together and sliding past one another."

He said, "It's almost like a rock stuck to the track of a sliding door." "It doesn't want to move smoothly because there are so many forces on it."

WHAT CAUSED THE MOST RECENT QAKE?

Saturday's magnitude 7.2 earthquake likely occurred along the Enriquillo-Plantain Garden fault zone, which cuts across Haiti's southwestern Tiburon Peninsula, according to the USGS.

It is the fault zone that caused the 2010 devastating earthquake. It's also likely to be the source of three other large earthquakes in Haiti, two of which decimated Port-au-Prince, between 1751-1806.

According to Gavin Hayes (USGS senior science advisor for earthquake and geologic hazards), earthquakes occur when tectonic plates are slowly moving against one another and create friction over time.

Hayes stated, "That friction builds up, and builds up, and eventually the strain that is stored there overcomes it." "And then the fault moves abruptly. This is what an earthquake looks like.

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WHY ARE EARTHQUAKES IN HAITI SO DIVASTATING?

It is a combination of several factors, including a seismically active region, a high density of 11,000,000 people and buildings that are often built to withstand hurricanes.

Concrete and cinder blocks buildings are strong enough to withstand strong winds, but they can be damaged or collapsed if the ground shakes. Bad building practices could also play a part.

The magnitude-7.0 earthquake that struck Haiti in 2010 caused extensive destruction and was closer to Port-au-Prince, a densely populated city. Haiti's government claimed that more than 300,000 people died in the earthquake, but a U.S. government report said it was between 46,000- 85,000.

Wendy Bohon, a geologist at Incorporated Research Institutions for Seismology, stated that "natural disasters are not real." "What you have are natural hazards that cross with vulnerable systems."

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WHAT IS THE FUTURE LIKE?

According to geologists, they can't predict the next earthquake.

Hayes, USGS said that "but we know that earthquakes such as this can cause similar-sized seismic events on the next section of the fault." "And it's quite dangerous in places that don’t have the building practices to withstand shaking.

Haiti is the Western Hemisphere's poorest country and continues to face challenges in building earthquake-resistant buildings.

Haiti was still recovering from Hurricane Matthew in 2016 and the 2010 earthquake. The country was plunged into political chaos after its president was assassinated.

While there have been success stories in Haiti of building earthquake-resistant structures, there has not been a central effort to do so, according to Mark Schuller, Northern Illinois University professor of anthropology, nonprofit and NGO studies and professor of anthropology.

Haiti's government is becoming weaker, and non-governmental organizations are focusing on their own projects.

"Haiti has technical knowledge. There are qualified architects. There are also city planners. Schuller stated that this is not the problem. Schuller stated that the problem is not lack of coordination funding or lack of political will by donors (to aid organizations).